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Balanced diet for strong bones

Australian women are being urged to eat a varied balanced diet to reduce their exposure to cadmium, after a major study linked the metal to reduced bone density.

Seventy seven WA women aged 50 years and over were recruited and their blood and urine was tested for the presence 11 metals, as well as biomarkers of bone and kidney health.

Lead researcher Anna Callan said the most striking result from the study at Edith Cowan University in WA was that the more cadmium that was detected in the women’s urine, the lower their bone density.

‘Even low levels of cadmium present in urine was associated with lower bone density in the whole body as well as specifically in the hip and spine region, potentially increasing the risk of osteoporosis in post-menopausal women’ she said; ‘Cadmium is found naturally in the soil at very low concentrations but we also know that certain agricultural and industrial practices can release more of the metal into the environment, which can lead to the presence of cadmium in the food chain.’

Fellow researcher and public health nutritionist associate professor Amanda Devine said because cadmium is present in so many foods, there isn’t one type of food you can avoid to limit exposure.
‘The best way to minimise your exposure to cadmium is to eat a varied diet.’

Devine said eating low-fat dairy food provides calcium which promotes healthy bone growth.
‘A diet rich in iron will reduce the amount of cadmium absorbed from your diet’ said Callan; ‘The relationship between iron intake and cadmium has been seen in international studies and also in some of our previous work.’

Callan said the study also revealed that blood zinc concentration was associated with reduced bone breakdown.

Blood zinc concentrations may be protective as they are associated with reduced bone breakdown, suggesting that a diet rich in zinc may also help to minimise the effects of cadmium exposure.